diff --git a/pkg/urbit/include/noun/imprison.h b/pkg/urbit/include/noun/imprison.h
index c68088eee..2123fb813 100644
--- a/pkg/urbit/include/noun/imprison.h
+++ b/pkg/urbit/include/noun/imprison.h
@@ -127,12 +127,12 @@
 
         /* u3i_string(): Produce an LSB-first atom from the C string [a].
         */
-          u3_noun
+          u3_atom
           u3i_string(const c3_c* a_c);
 
         /* u3i_tape(): from a C string, to a list of bytes.
         */
-          u3_atom
+          u3_noun
           u3i_tape(const c3_c* txt_c);
 
         /* u3i_list(): list from `u3_none`-terminated varargs.
diff --git a/pkg/urbit/noun/imprison.c b/pkg/urbit/noun/imprison.c
index 77feae7f6..b34b9d884 100644
--- a/pkg/urbit/noun/imprison.c
+++ b/pkg/urbit/noun/imprison.c
@@ -541,7 +541,7 @@ u3i_qual(u3_noun a, u3_noun b, u3_noun c, u3_noun d)
 
 /* u3i_string(): Produce an LSB-first atom from the C string [a].
 */
-u3_noun
+u3_atom
 u3i_string(const c3_c* a_c)
 {
   return u3i_bytes(strlen(a_c), (c3_y *)a_c);
@@ -549,7 +549,7 @@ u3i_string(const c3_c* a_c)
 
 /* u3i_tape(): from a C string, to a list of bytes.
 */
-u3_atom
+u3_noun
 u3i_tape(const c3_c* txt_c)
 {
   if ( !*txt_c ) {